The present invention of the instant application relates to an engine device.
Conventionally, for example, regarding ships such as tankers and transport vessels or power generation facilities on land, diesel engines have been utilized as the driving source thereof. However, much of toxic substances such as nitride oxides, sulfur oxides, particulate matter, which are impediments to environmental preservation, are included in the exhaust gas of the diesel engine. Accordingly, in recent years, gas engine devices and the like, which can reduce emissions of toxic substances, have been widespread as engines substituted for the diesel engines.
Regarding what is called the gas engine devices that generate motive power by use of fuel gas such as natural gas, mixed gas in which air is mixed with the fuel gas is supplied to cylinders and combusted (see Japanese Unexamined Patent Application Publication No. 2003-262139). In the gas engine disclosed in Japanese Unexamined Patent Application Publication No. 2003-262139, the fuel gas is mixed with air compressed by a supercharger and supplied to the cylinders. Regarding the aforementioned gas engine devices, a throttle valve is provided between the supercharger and an intake manifold for drawing air into the cylinders, and the opening degree of the throttle valve is controlled, thereby adjusting an air-to-fuel ratio.